Section 47.50  Non-Conforming Uses

a)         Regulations Not Retroactive – Those surface regulations prescribed by this Part shall not be construed to require the removal, lowering or other changes or alteration of any structure or tree not conforming to the regulations as of the effective date of this Part or otherwise interfere with the continuance of any non-conforming use.  Nothing contained herein shall require any change in the construction, alteration, or intended use of any structure, the construction or alteration of which was begun prior to the effective date of this Part and is diligently prosecuted.

b)         Marking and Lighting

1)         Notwithstanding the provisions of Section 47.50(a), the owner of an existing non-conforming structure is hereby required to permit the installation, operation and maintenance thereon of such markers and lights as shall be deemed necessary by the Department to indicate to operators of aircraft in the vicinity of the airport, the presence of such airport hazards, all to be performed at the expense of the Greater Rockford Airport Authority.

2)         In determining the necessity for such markers and lights, the Department shall consider all relevant conditions, including but not limited to, the traffic patterns, volume and type of aircraft at the airport, the general weather patterns in the vicinity, the topography of the airport and the surrounding area, and the height of the structure and its proximity to the approach and transition slopes of the existing runways.